Clinical Characteristics And Prognosis Analysis Of Pancreatic Neuroendocrine Tumors

Background:Neuroendocrine neoplasms(NEN)are rare tumors,which originate from a group of peptidergic neurons and neuroendocrine cells.With the development of gastrointestinal endoscopy and imaging technology,more and more pancreatic neuroendocrine neoplasms are discovered.The pancreas,as a good site for neuroendocrine neoplasms,has an increasing annual incidence.However,due to the lack of large databases on neuroendocrine neoplasms in China,most of which are single-center clinical data,so there are relatively few studies on the clinical characteristics and prognosis of pancreatic neuroendocrine neoplasms(pNEN)in China,According to current clinical research,the factors that affect the prognosis of pNEN include age,tumor size,pathological grade,clinical stage,and whether or not surgery.It can be seen that the pathological grade of the tumor is of the cut-off value in predicting the prognosis of the patient.According to the degree of differentiation,pNEN is divided into well differentiated neuroendocrine tumors(NET)and poorly differentiated neuroendocrine carcinomas(NEC).With the deepening of the pNEN research,although the guide recommends the Ki-67 index of 3%to divide NET G1 and NET G2.But there are a few studies that consider the Ki-67 index to be 5%as the cut-off value for dividing NET G1 and NET G2.Compared to the Ki-67 index of 3%,it is more valuable for prognosis.For the treatment of pNEN,surgery is the only way to cure.The guidelines recommend that patients with tumors of more than 2 cm in size should choose surgical treatment if they meet surgical indications.However,for patients whose tumor size is less than 2 cm,current treatment is controversial,especially for patients with non-functional pNEN whose tumor size is less than 2 cm.There are few studies on whether choosing surgery is more beneficial to patients.Therefore,in view of the current controversy in the pNEN Institute,this study mainly retrospectively analyzed the clinical characteristics and prognosis of pNEN in our center.This study also analyzed the cut-off value for dividing NET G1 and NET G2.Hoping that it would provide clinical reference value.At the same time,this study retrospectively analyzed the clinical features of non-functional pNET with tumor size less than or equal to 2 cm,and further analyzed the related risk factors affecting its prognosis.Methods:A retrospective analysis of patients presented at the China-Japan Friendship Hospital of the Ministry of Health and diagnosed as pNEN from January 2012 to June 2019.A total of 173 pNEN patients were analyzed for clinical medical records.The factors affecting the prognosis were analyzed using univariate and multivariate analysis.The contingency table chi-square test or fisher exact test was used for comparison between groups.The area under the ROC curve was used to calculate the cut-off value.Results:Among 173 patients with pNEN,there were 92 males and 81 females.There were 167 cases of well differentiated pNET and 6 cases of poorly differentiated pNEC.There were 152 cases of non-functional pNEN and 21 cases of functional pNEN.There were 168 cases of sporadic pNEN and 5 cases of MEN-1 related pNEN.There were 56 cases of pNEN in the head of the pancreas,10 cases of pNEN in the body of the pancreas,30 cases of pNEN in the tail of the pancreas,and 77 cases of pNEN in the tail of the pancreas.As of June 30,2019,there were 140 patients survived and 33 died.There were 6 cases of functional pNEN and 27 cases of non-functional pNEN in the death group.There were 8 cases of NET G1,14 cases of NET G2,7 cases of NET G3 and 4 cases of NEC G3 in the death group.In the death group,there were 2 cases of stage ?,30 cases of stage ?,and 1 case of unknown stage.The median survival time for this group of patients was 35 months.The 3-year and 5-year survival rates were 88.4%and 84.4%,respectively.Using the area under the ROC curve to calculate the cut-off value for dividing NET G1 and NET G2 is 5.5%.Survival analysis was performed on patients with NET G1 and NET G2 according to Ki-67 index of 3%and 5.5%,respectively.In this group,if the ki-67 index was 5.5%,the survival prognosis of patients in the two groups was statistically significant(p=0.04).If the ki-67 index was 3%,the survival prognosis of the two groups was not statistically significant(p=0.867).The clinical characteristics of 19 patients with tumor size less than or equal to 2 cm of non-functional pNETs were analyzed,and further univariate analysis was conducted to analyze the factors affecting the disease progression of the patients.In this study,it was found that the clinical stage,pathological grade and surgery of the tumor were risk factors affecting the progress of the patient's disease.If the Ki-67 index is 5.5%to divide NET G1 and NET G2,their p-values are 0.017,0.005,0.032,respectively.If the Ki-67 index is 3%to divide NET G1 and NET G2,their p-values are 0.017,0.036,0.032,respectively.The clinical features of non-functional pNET with tumor size less than or equal to 2 cm were analyzed.Pathological grade is a risk factor that affects the prognosis of patients(p=0.024),and a ki-67 index greater than 5.5%is a high risk factor that affects postoperative recurrence.Conclusion:Tumor clinical stage and surgical choice are independent risk factors that affect the prognosis of patients with pNEN.Pathological grade,clinical stage,and surgery are risk factors for disease progression in patients with non-functional pNET whose tumor size is less than or equal to 2 cm.Combined with clinical practical feasibility,it is recommended that the ki-67 index greater than 5%is a risk factor for postoperative recurrence in patients with non-functional pNET whose tumor size is less than or equal to 2 cm.Combined with clinical practical recommendations,the cut-off value of pNET G1 and pNET G2 is divided by Ki-67 index of 5%.